# Remove lowest fraction from FTClusterCreator

Channel position and fraction used to be calculated with

```
float m_lowestFraction = -0.25
float clusPosition = wsumPosition / totalCharge;
unsigned int chan = std::floor( clusPosition - m_lowestFraction );
float fractionChanPosition = ( clusPosition - chan );
int frac = int( 2 * ( fractionChanPosition - m_lowestFraction ) );
```

Which is a bit arcane, and seems to be equivalent to the simpler:

```
float clusPosition = wsumPosition / totalCharge;
int rounded = std::round(2*clusPosition);
int chan = rounded/2;
int frac = rounded & 1;
```

We need to find a way to test the resulting resolutions and efficiencies, and @sesen 's opinion on this would be very precious